Sudeshna Nag, Shikha Rani, Sarmistha Mahanty, Christin Bissig, Pooja Arora, Cristina Azevedo, Adolfo Saiardi, Peter van der Sluijs, Cedric Delevoye, Guillaume van Niel, Graca Raposo, Subba Rao Gangi Setty
Sorting endosomes (SEs) are the regulatory hubs for sorting cargo to multiple organelles, including lysosome-related organelles, such as melanosomes in melanocytes. In parallel, melanosome biogenesis is initiated from SEs with the processing and sequential transport of melanocyte-specific proteins toward maturing melanosomes. However, the mechanism of cargo segregation on SEs is largely unknown. Here, RNAi screening in melanocytes revealed that knockdown of Rab4A results in defective melanosome maturation. Rab4A-depletion increases the number of vacuolar endosomes and disturbs the cargo sorting, which in turn lead to the mislocalization of melanosomal proteins to lysosomes, cell surface and exosomes...
September 20, 2018: Journal of Cell Science